Overlapping generations models with or without production or a portfolio demand for money display a fundamental indeterminacy. Expectations matter; and they are not, in the short run, constrained by the hypotheses of agent optimization, rational expectations, and market clearing. No short run...

When government liabilities (including money) are held in private portfolios only as stores of value, and do not provide additional benefits (as liquidity services), the real variables in an economy with uncertainty are not affected by the government's trading in assets. There are also policies...

A feasible social state is irreducible if and only if, for any non-trivial partition of individuals with two groups, there exists another feasible social state at which every individual in the first group is equally well-off and someone strictly better-off. Competitive equilibria decentralize...

Competitive equilibrium allocations are indeterminate when the net trades in commodities are constrained, while the asset market is incomplete.

Let assets be denominated in an a priori specified numeraire. Whether or not the asset is complete, a competitive equilibrium exists as long as arbitrage is possible when assets are free. Generically, the set of competitive equilibria is finite, and the equilibrium prices and allocations in the...

Under the assumption of common priors, if the information partitions of two agents are finite, then simply by communicating back and forth and revising their posteriors the two agents will converge to a common equilibrium posterior, even though they may base their posteriors on quite different...

In an incomplete asset market, firms assign values to investment plans by projecting their payoffs on the span of the payoffs of marketed assets; equivalently, firms employ the Capital Asset Pricing Model. This is a criterion that does not require firms to possess information, such as the...

When the asset market is incomplete, competitive equilibria are constrained suboptimal, which provides a scope for pareto improving interventions. Price regulation can be such a pareto improving policy, even when the welfare effects of rationing are taken into account. An appealing aspect of...